1. Field of the Invention
This invention relates to logical networks. More particularly, the invention relates to integrated array logic that is (a) electrically personalized as a function of time, and/or (b) fixed in a semiconductor material.
2. Description of the Prior Art
Integrated logic networks are of two general types. The first type is randomly arranged logic elements that may be discrete or integrated AND, OR an Invert elements which are connected as desired and to which electrical signals are supplied to achieve a logical result. A second logic network is array logic. A matrix of logical elements can be assembled to provide fixed answers, e.g., a table lookup for a plurality of input signals. Both logic networks have certain advantages and disadvantages. The random logic elements can be densely packed and the speed of logic execution can be optimized. However, random logic elements require significant inventory or stockpiling to have available the required logic functions for data processing system designers to achieve desired objectives. Also, there is significant design turnaround time required to generate a new logic function. System design and development is hampered by the long lead time in fabricating new logic elements. Array logic, in contrast, has few part numbers and permits fast turnaround time in designing new data processing systems. However, array logic requires significantly more semiconductor area than random logic to perform a desired logic function. Execution time for a logic function may also be longer in an array logic element than in a random logic element.
Array logic elements are generally of two types. One type has a fixed personality which is set in manufacture, as for example, read-only or read-mostly memories. A second array logic type is programmable whereby output signals are returned to the input of an array to alter the logic outputs. Array logic elements permit complex logic functions to be easily designed. Array logic elements that require minimum semiconductor area and few part numbers will permit improvements in the performance and versatility of small data processing systems.